Conventionally, damage to the health of medical professionals who handle a cytotoxic medicine used in cancer chemotherapy and the like is regarded as a problem. The reason for this is as follows: cytotoxic medicines are usually distributed in a state of being sealed in a medicine container, but medical professionals need to pierce a lid portion of such a container with a needle set in a syringe, and dissolve, dilute, mix, and extract the medicine within the container, and during such operations, there are many cases in which the medicine leaks and volatilizes via a needle hole formed by piercing the lid portion of the medicine container with the needle of the syringe, thus exposing medical professionals to the medicine.
In order to solve the above problem, Patent Literature 1 and Patent Literature 2 disclose a lid cover that is mounted to a lid portion of a medicine container so as to cover the lid portion when extracting a medicine. The lid cover of Patent Literature 1 is configured to secure a certain closed space between the ceiling face portion of the lid cover that is pierced with a needle of a syringe and the lid portion of the medicine container. As a result, even if a medicine leaks via a needle hole formed in the lid portion of the medicine container, the leaked medicine is contained in the closed space, and leakage to the outside space is suppressed.
On the other hand, Patent Literature 2 discloses a lid cover provided with a cap-shaped housing that is mounted to a mouth portion of a medicine container. The housing of the lid cover is formed of hard plastic, and a piercing hole is formed in the central portion of the housing. Also, the lid cover is characterized in having a rubber sheet that blocks the piercing hole, and in that the rubber sheet has a protruding shape protruding toward the rubber plug side of the medicine container. Furthermore, in the disclosure, it is preferable that the internal space between the mouth portion of the medicine container and the lid cover is in communication with the outside via a filter member. This is for resolving the generation of positive pressure in the internal space due to the occurrence of pressure difference between the outside and the inside of a syringe when the needle of the syringe is pulled out from the rubber sheet. Accordingly, when positive pressure is generated in the internal space, there is a risk that the medicine leaks, but positive pressure generated in the internal space is resolved by providing the filter member that is in communication with the outside.